So I was excited to learn about a team at Indiana University-Purdue University Indianapolis (IUPUI) that has been looking at the science behind how dogs locate explosives, such as Composition C-4 (a plastic explosive used by the U.S. military). Their first findings, the culmination of a four-year study funded by the U.S. Department of Defense, found that dogs react best to working with the actual explosive. This sounds like a no brainer, but apparently it's common to use products that mimic the odor of C-4 for training purposes. Previous studies suggested that certain non-explosive chemicals emitted by C-4 caused dogs to alert, which is why many people were using the faux substances in place of real explosives.

In the first phase of the study. IUPUI researchers discovered that the non-explosive chemicals given off by C-4 mimics are also present in a variety of everyday plastic objects. Objects tested included PVC pipes, electrical tape, movie tickets, a plastic grocery bag, and plastic food wrapping. You can see how problematic that is and why dogs trained with mimics would be deemed unreliable.

The second phase tested 33 canines from the Department of Defense, Department of Justice, Amtrak, and other agencies that were trained on real explosives. The dogs were exposed to specific vapors found in C-4, one at a time. The pups failed to respond, demonstrating that if dogs are trained on the full scent, they will only detect real explosives (all of the scents combined) and not to singular scents that may be found in the environment.

"The canines are not easily fooled," says John Goodpaster, Ph.D., associate professor of chemistry and chemical biology and director for the Forensic and Investigative Sciences Program in the School of Science at IUPUI. "You can't pick and choose components of explosive odors and expect the dog to respond," Goodpaster said. "Dogs are specific and it's the full scent that causes them to alert." Of course more research must be done, but this study shows that having more consistent training protocols has the potential to help make sniffing dogs more reliable. It also establishes some of the science needed for canine detection to be used as legally admissible evidence in court. I hope to see more studies in the coming years!